An insect known as the elk bot fly, found in Sweden, strongly resembles a bumble bee and has a unique method of spreading its progeny—by injecting larvae into your eyes.

The bot fly larvae is a parasite that mainly feed on the mucus of elk and deer.

A full grown bot fly measures around 2 centimeters and looks like a hairy bumble bee. After mating, the female looks for a host for her offspring, which usually happens to be the nostril of an elk or a deer. Unfortunately, the bot fly will occasionally mistake a human eye for a suitable host.

When the larvae are in the host’s nostrils, they feed on mucus until they grow big enough to wriggle their way down its throat. The movements tickle the nose of the animal, which sneezes them out together with mucus and blood, where they continue into their final stage of development.

According to entomologists, a woman suffered an attack in a central Swedish forest last autumn after a fly hovering close to the woman’s face shot larvae into one of her eyes.

About 30 larvae were removed from her eye, but she had a persistent feeling of “creeping larvae” in the eye and nose area. Later that day, two more were removed.

Victims have described bot fly attacks as having the same sensation of being slapped in the face by a branch.